/Engine/Plugins/Experimental/SlateScreenReader/Source/SlateScreenReader/Public/SlateScreenReaderEngineSubsystem.h
Returns the volume text to speech will be speaking at for a screen reader user. Value is between 0.0f and 1.0f. If the provided user Id doesn't exist, 0.0f will be returned.
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category="SlateScreenReader") float GetSpeechVolume ( UPARAM(DisplayName="Screen Reader User Id") int32 InUserId ) const